Currently there seems to be some network issues with Single sign on. You can directly connect to the server url https://yp-dashdb-small-01-lon02.services.eu-gb.bluemix.net:8443 and login using the credentials from your VCAP_SERVICES environment variable. To see the VCAP_SERVICES env variable, you can bind the service to an app, and in the app home page, click on "Show Credentials" for the dashDB service instance.